<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>01_流程控制</title>
</head>
<body>

<script>
    //1.顺序结构
    console.log('1');
    console.log('2');
    console.log('3');
    //2.分支结构
    let username = 'tom';
    /*if(!username){
        alert('用户名不能为空!')
    }else {
        alert('欢迎'+username+'回归!')
    }*/
    //3.选择分支
    let gender = 1;
    switch (gender){
        case 1:
            console.log('男');
            break;
        case 2:
            console.log('女');
            break;
        default:
            console.log('未知');
    }
    //4.循环结构
    let names = ['张三','李四','王五','赵六','钱七'];
    for (let i = 0; i < names.length; i++){
        console.log(names[i]);
    }
    //如果用var定义变量,循环结束后,i的值在此处还可以打印出来!
    //console.log('循环结束!'+i);

    //增强for循环
    //let n 表示当前遍历到的元素
    for (let n of names){
        console.log(n);
    }
</script>
</body>
</html>